Steve Carlin created IMPALA-14456:
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             Summary: Calcite planner: Need a better estimate for deciding if a 
runtime filter is needed
                 Key: IMPALA-14456
                 URL: https://issues.apache.org/jira/browse/IMPALA-14456
             Project: IMPALA
          Issue Type: Sub-task
            Reporter: Steve Carlin


There is some code in ImpalaLoptOptimizeJoinRule which decides if a runtime 
filter should cause the left side and a right side of a join to be swapped.  It 
compares row counts from the deepest left side versus the row count on the 
right side.

This isn't a good comparison because we really want to associate a cost with 
the right side.  

There was some initial simplistic code that also multipled the row counts with 
the average row size, but that was incorrect because only projected columns 
come out of the deepest left side, not the whole row.

This should be re-examined.



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